This invention deals generally with agricultural equipment and more specifically with an apparatus to complete the wrapping of a partially wrapped bale produced by a xe2x80x9cround balerxe2x80x9d.
Round balers with the capability of wrapping the bales in plastic film have become common machines on the agricultural landscape. The benefits of the wrapped bales are that they protect the crop material from the weather, encourage crops to ferment to enhance the nutritional value, and eliminate the need for costly storage facilities. Some machines in the prior art are built to pick up formed round bales from the fields, wrap them, and then put them back down, but such an approach requires significant manpower and machinery. Other machines can be pulled behind a round baler, accept the bale from the baler and wrap it as the baler forms the next bale.
However, there are several round balers that take advantage of the action of the baler itself, the rotation of a cylinder of crop material, to wrap the cylinder by inserting plastic film from a supply roll into the bale forming chamber. This allows the bale rotation in the forming chamber to catch the plastic film and wrap it around the bale""s cylindrical surface. A particular example of this type of round baler is disclosed in U.S. Pat. No. 5,230,193 by Underhill et al. With such a wrapper, it is possible to furnish excess wrapping material extending off the non-cylindrical ends of cylindrical bales for later use in sealing the ends.
One approach in the prior art has been to build machines that rotate the bale around its axis to wrap the cylindrical surface and to sequentially or simultaneously rotate the bale in a horizontal plane to wrap the ends of the bale. Another approach has been to use a so called satellite system in which the bale is rotated around its axis to cover the cylindrical surface, and the ends of the cylindrical bale are wrapped by a supply roller that moves around the bale in a horizontal plane.
The problem with such machines are their great complexity. Almost all of them operate independently of the baler itself, even if they are towed behind the baler. Furthermore, they all must produce a duplicate motion that the baler has just completed, the rotation of the cylindrical bale around its cylindrical axis.
It would be very beneficial to have a simple machine that merely wraps the ends of a bale, the cylindrical surface of which was already wrapped by a round baler, and to include that machine right on the frame of the round baler, so that it could be operated by the baler operator and even use the same continuous film material that covers the cylindrical surface.
The present invention is a finishing wrapper structure added to the rear of a prior art round baler to complete the wrapping of a bale that has only its cylindrical surface wrapped with plastic film. The finishing wrapper of the invention is constructed on a base frame that is essentially a pivoting rearward extension of the frame of the round baler, and the finishing wrapper receives the ejected partially wrapped bale while the plastic film on the bale is still attached to the supply roll of the film that is in the baler. The bale is captured by a slightly xe2x80x9cVxe2x80x9d shaped table that prevents the bale from rolling off the back of the finishing wrapper because the table is oriented with its higher sides aligned transverse to the direction of motion of the baler and parallel to the axis of the ejected bale. The table is then rotated 90 degrees to reorient the bale with its cylindrical axis aligned with the baler""s direction of motion.
Two clamping arms are attached to the base frame of the finishing wrapper, with one arm on each side of the base frame at a location approximately aligned with the sides of the baler and on opposite sides of the reoriented bale. Each clamping arm is pivotable and has a rotating clamp on its end remote from the base frame, with the rotating clamps formed essentially as short beams with paddle like ends that angle slightly inward toward the bale. The rotational motion of each clamp is powered by a hydraulic motor mounted on the clamping arm near the rotating clamp and is transferred to the rotating clamp by a conventional chain drive.
The clamping arms themselves can pivot both toward each other to clamp tightly onto the bale and in an arc toward the rear of the finishing wrapper to release a bale on the ground behind the apparatus. The pivoting action of the clamping arms and the rotation of the xe2x80x9cVxe2x80x9d shaped table are all conventionally powered by hydraulic cylinders.
The actions of the finishing wrapper are surprisingly straightforward. When the tailgate of the conventional baler opens, instead of the bale being ejected onto the ground and the plastic film that is wrapped around its cylindrical surface being cut free from the supply roll, the bale is caught by the xe2x80x9cVxe2x80x9d shaped table of the finishing wrapper. Furthermore, the plastic film is not cut, but trails out of the baler and stays on the bale. Then the table is rotated 90 degrees so that the unwrapped ends of the bale are now facing the front and rear of the finishing wrapper. This rotation causes the plastic film to twist and wrap from what is now one side of the bale toward the end of the bale facing the round baler.
The clamping arms, with the rotating clamps oriented in an approximately horizontal plane, are now activated to move inward and push the rotating clamps tightly onto the opposite cylindrical surfaces of the bale. After the rotating clamps are tightly gripping the cylindrical surface of the bale, the clamping arms are pivoted rearward in an arc that raises the rotating clamps to lift the bale off and clear of the table. The bale is then rotated by the rotating clamps so that the rotation pulls the plastic film onto the bale, and, as the rotation continues, it turns the bale end over end. This motion continues until the bale is fully wrapped, at which time the plastic film is conventionally cut within the round baler. During the wrapping operation the clamping arms are continuously pivoted farther toward the rear of the machine, so that, as the wrapping is completed, the arms are ready to release the bale onto the ground. The various parts of the finishing wrapper then return to their initial positions as the baler again begins its bale forming action.
The invention thereby provides a fully wrapped bale with a relatively simple structure that can be added to a conventional prior art round baler design and can be operated without additional personnel. An even more interesting aspect of the invention is that, based upon actual field tests of the invention, the entire finish wrapping procedure takes only about 20 seconds.